Southwestern Deserts

August, 2009
Regional Report

Start Vegetable Transplants

Sow seeds indoors of cabbage family plants such as broccoli, cauliflower, cabbage, and Brussels sprouts. You'll have a jumpstart with these transplants when the cool-season planting season begins in late September or early October.

Pull Summer Weeds

Annual summer weeds sprout and spread quickly after rain arrives in the form of monsoon thunderstorms. Pull them while they're still small and put them in the compost pile. They are a good source of nitrogen. Never let weeds go to seed. They'll produce zillions of seeds, which you'll be pulling the seedlings of for years.

Add Iron to Plants

Non-native plants often show signs of iron chlorosis this time of year. Lack of iron shows up as yellowing new leaves while veins stay green. If there's too much water in the soil from summer thunderstorms or overwatering, iron that's in the ground can't be taken up by plants. Wet soils displace oxygen, which plant roots require to absorb iron. If symptoms appear and you aren't overwatering, apply iron chelated or ferrous sulfate fertilizers, which roots absorb.

Care for Containers

Many containers need daily watering during the summer heat. Make sure the water soaks through the soil and root system, and doesn''t just run down the sides of the pot. If containers have dried out and soil has shrunk away from the sides of the pot, try plunging the entire container into a larger container full of water to soak and rehydrate.

Maintain Summer Lawns

Water Bermudagrass every 2 to 3 days in the low desert, less frequently if you live at higher and cooler ranges. Water should penetrate 8 to 10 inches, which is how deep the root system is. Examine the entire lawn for areas that may not be receiving adequate water. Set out empty tuna or cat food cans around the lawn before the sprinklers run. The water level in the cans will help you determine if some areas aren't receiving equal water. Fertilize monthly with a 21-7-14 ratio. Do not fertilize more frequently; overfertilizing promotes excessive growth, which needs more water and mowing.